Which term describes a steady state in which the internal conditions of an organism are kept within a narrow range without regard to the external conditions?
a. regulatory homeostasis.
b. negative feedback.
c. conformational homeostasis.
d. thermoregulation.

The correct answer is A. Regulatory homeostasis

Explanation:

In regulatory homeostasis, the internal condition of an organism remains within a narrow range irrespective of the external environment condition. This steady-state is necessary for the cell to live and perform important metabolic functions.

Some of the regulatory homeostasis performed by the body is maintaining pH of the blood, ionic balance in the cell, temperature of the body, blood sugar level, etc.  

Negative feedback loop is involved when homeostasis is performed for example if the pH of blood increased the this negative feedback loop will function and bring back the pH at normal value. So the right answer is A.

i think the miocene epoch spans the time from 23 million to 12 million years ago.

a

explanation: